Conventionally, a service in which information posted from a user can be browsed by other users (hereinafter referred to as “posting information publishing service”) is known. An example of the posting information publishing service is a CGM (Consumer Generated Media) service such as a blog, a mini-blog, and SNS (Social Network Service). In the posting information publishing service, for example, a user can recommend an item for sale, which the user found on the Internet, to other users. In this case, the user inputs a sentence to be posted in an input area displayed based on an HTML (HyperText Markup Language) document or the like on a screen of a terminal apparatus. For example, Patent Literature 1 describes that a user inputs a message or the like introducing an item for sale in an input field in an introduction input form screen displayed on a screen.